Do baby cry remembering someone close??

Recently my mother went back to her place..she was staying with me from the time of delivery

And look after my baby all the time... she used to play with him for long hours... but its been two days she went back to her place and today while i was doing FaceTime with her.. my baby recognised her voice n started looking arround in the room to find her... and started crying

is this possible?? Can babies miss someone???

He is judt 5 month old right now..